Institute of Biomedical Sciences
Extinction of Blood Pressure and Heart Rate Responses to Conditioned Fear
Poster Number
12
Document Type
Poster
Status
Graduate Student - Doctoral
Publication Date
Spring 2018
Abstract
Background: Post-traumatic stress disorder (PTSD) is characterized by an impaired ability to extinguish fear associations that trigger exaggerated neurophysiological responses, which may contribute to increased cardiovascular (CV) risk. The objective of this study was to evaluate the effects of learned inhibition or extinction on the conditioned cardio-autonomic response during fear memory recall. We hypothesized that extinction training would lead to a temporary reduction of conditioned heart rate (HR) and systolic blood pressure (SBP) responses.
Methods: In male C57BL/6 mice, Pavlovian fear conditioning combined with simultaneous in-vivo telemetry was used to assess CV and behavioral measures in home-cage and testing contexts. The conditioned CV response was evaluated during short-term (STR) (1-hour post-extinction) and long- term recall (LTR) (2 weeks post-extinction) of the CS in the home-cage.
Results: Freezing in response to the CS from Day 1 to Day 2 was reduced in fear conditioned mice (80% ± 7 vs. 57% ± 11; p
Conclusions: These data demonstrate that both short and long-term recall of fear memory elicit a conditioned blood pressure response that can be temporarily attenuated by extinction training. Furthermore, these data suggest that conditioned blood pressure and heart rate responses may vary in their sensitivity to inhibitory learning.
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Open Access
1
Extinction of Blood Pressure and Heart Rate Responses to Conditioned Fear
Background: Post-traumatic stress disorder (PTSD) is characterized by an impaired ability to extinguish fear associations that trigger exaggerated neurophysiological responses, which may contribute to increased cardiovascular (CV) risk. The objective of this study was to evaluate the effects of learned inhibition or extinction on the conditioned cardio-autonomic response during fear memory recall. We hypothesized that extinction training would lead to a temporary reduction of conditioned heart rate (HR) and systolic blood pressure (SBP) responses.
Methods: In male C57BL/6 mice, Pavlovian fear conditioning combined with simultaneous in-vivo telemetry was used to assess CV and behavioral measures in home-cage and testing contexts. The conditioned CV response was evaluated during short-term (STR) (1-hour post-extinction) and long- term recall (LTR) (2 weeks post-extinction) of the CS in the home-cage.
Results: Freezing in response to the CS from Day 1 to Day 2 was reduced in fear conditioned mice (80% ± 7 vs. 57% ± 11; p
Conclusions: These data demonstrate that both short and long-term recall of fear memory elicit a conditioned blood pressure response that can be temporarily attenuated by extinction training. Furthermore, these data suggest that conditioned blood pressure and heart rate responses may vary in their sensitivity to inhibitory learning.